Research output: Contribution to journal › Article › peer-review
Crustal nature and origin of the Russian Altai : Implications for the continental evolution and growth of the Central Asian Orogenic Belt (CAOB). / Cai, Keda; Sun, Min; Buslov, M. M. et al.
In: Tectonophysics, Vol. 674, 02.04.2016, p. 182-194.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Crustal nature and origin of the Russian Altai
T2 - Implications for the continental evolution and growth of the Central Asian Orogenic Belt (CAOB)
AU - Cai, Keda
AU - Sun, Min
AU - Buslov, M. M.
AU - Jahn, Bor ming
AU - Xiao, Wenjiao
AU - Long, Xiaoping
AU - Chen, Huayong
AU - Wan, Bo
AU - Chen, Ming
AU - Rubanova, E. S.
AU - Kulikova, A. V.
AU - Voytishek, E. E.
PY - 2016/4/2
Y1 - 2016/4/2
N2 - The Central Asian Orogenic Belt is a gigantic tectonic collage of numerous accreted terranes. However, its geodynamic evolution has been hotly debated primarily due to incomplete knowledge on the nature of these enigmatic terranes. This work presents new detrital zircon U-Pb and Hf isotopic data to constrain the crustal nature and origin of the Russian Altai, a critical segment of Altai-Mongolian terrane. The youngest zircon 206Pb/238U ages of 470 Ma constrain that the Terekta Formation, previously envisaged as Precambrian basement, was actually deposited after the Middle Ordovician. As for the three more sedimentary sequences above the Terekta Formation, they have youngest zircon 206Pb/238U ages of 425 Ma, 440 Ma and 380 Ma, respectively, indicating their depositions likely in the Late Silurian to Devonian. From all analyses, it is noted that many zircon U-Pb ages cluster at ca. 520 Ma and ca. 800 Ma, and these zircons display oscillatory zoning and have subhedral to euhedral morphology, which, collectively, suggests that adjacent Neoproterozoic to Paleozoic igneous rocks were possibly dominant in the sedimentary provenance. Additionally, a few rounded Archean to Mesoproterozoic zircon grains are characterized by complex texture, which are interpreted as recycling materials probably derived from the Tuva-Mongolian microcontinent. Precambrian rocks have not been identified in the Russian Altai, Chinese Altai and Mongolian Altai so far, therefore, Precambrian basement may not exist in the Altai-Mongolian terrane, but this terrane probably represents a large subduction-accretion complex built on the margin of the Tuva-Mongolian microcontinent in the Early Paleozoic. Multiple episodes of ridge-trench interaction may have caused inputs of mantle-derived magmas to trigger partial melting of the newly accreted crustal materials, which contributed to the accretionary complex. During accretionary orogenesis of the CAOB, formation of such subduction-accretion complex is likely ubiquitous, indicating continental crust growth by both lateral accumulation and vertical basaltic injection.
AB - The Central Asian Orogenic Belt is a gigantic tectonic collage of numerous accreted terranes. However, its geodynamic evolution has been hotly debated primarily due to incomplete knowledge on the nature of these enigmatic terranes. This work presents new detrital zircon U-Pb and Hf isotopic data to constrain the crustal nature and origin of the Russian Altai, a critical segment of Altai-Mongolian terrane. The youngest zircon 206Pb/238U ages of 470 Ma constrain that the Terekta Formation, previously envisaged as Precambrian basement, was actually deposited after the Middle Ordovician. As for the three more sedimentary sequences above the Terekta Formation, they have youngest zircon 206Pb/238U ages of 425 Ma, 440 Ma and 380 Ma, respectively, indicating their depositions likely in the Late Silurian to Devonian. From all analyses, it is noted that many zircon U-Pb ages cluster at ca. 520 Ma and ca. 800 Ma, and these zircons display oscillatory zoning and have subhedral to euhedral morphology, which, collectively, suggests that adjacent Neoproterozoic to Paleozoic igneous rocks were possibly dominant in the sedimentary provenance. Additionally, a few rounded Archean to Mesoproterozoic zircon grains are characterized by complex texture, which are interpreted as recycling materials probably derived from the Tuva-Mongolian microcontinent. Precambrian rocks have not been identified in the Russian Altai, Chinese Altai and Mongolian Altai so far, therefore, Precambrian basement may not exist in the Altai-Mongolian terrane, but this terrane probably represents a large subduction-accretion complex built on the margin of the Tuva-Mongolian microcontinent in the Early Paleozoic. Multiple episodes of ridge-trench interaction may have caused inputs of mantle-derived magmas to trigger partial melting of the newly accreted crustal materials, which contributed to the accretionary complex. During accretionary orogenesis of the CAOB, formation of such subduction-accretion complex is likely ubiquitous, indicating continental crust growth by both lateral accumulation and vertical basaltic injection.
KW - Accretionary orogenesis
KW - Altai-Mongolian terrane
KW - Central Asian Orogenic Belt
KW - Continent crustal growth
KW - Subduction-accretion complex
UR - http://www.scopus.com/inward/record.url?scp=84960194210&partnerID=8YFLogxK
U2 - 10.1016/j.tecto.2016.02.026
DO - 10.1016/j.tecto.2016.02.026
M3 - Article
AN - SCOPUS:84960194210
VL - 674
SP - 182
EP - 194
JO - Tectonophysics
JF - Tectonophysics
SN - 0040-1951
ER -
ID: 25380423